Stitch-forming mechanism for sewing-machines.



No. 703,812 Patented July I, I902.

L. onnznuoux.

STITCHFORMNG MECHANISM FOR SEWING MACHINES.

' (Applichtion filed Sept. 11, 1897. "lo M o d al 4 sheets-she th.

- N0. 703.8I2. I Patented m I902.

L. UNDEBDONK. STITCH FORMING MECHANISM FOR SEWING MACHINES.

(Application med'se e. 11, 1897. (No Moflel.) 4 Sheets-Sheet '3.-

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No. 703,312; Patented July |,.1902.

L. DNDERDUNK. I STITCH FUBMING MECHANISM FOR SEWING MACHINES.(Application filed Sept. u,'1s91.j (No Model.) 4 Sheets-8heet 4.-

- 3 'ewtoz lwfl-"mama I ablioz meq LANSING ONDERDONK, OF BOSTON,MASSACHUSETTS, ASSIGNOR TO THE UNION SPECIAL SEWING MACHINE COMPANY, ACORPORATION OF ILLIN OIS.

STITCH-FORMING MECHANISM FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 703,812, dated July 1,1902.

Application filed September 11, 1897. Serial No. 651,293. (No model.)

To all whom, it may concern:

Be it known that I, LANSING ONDERDONK, a citizen of the United States,residing at Boston, in the county of Suffolk, State of'Ma'ssachusetts,have invented certain new and useful Improvements in Sewing-lVIachines,of which the following is a description, reference being bad to theaccompanying'drawings, and to the lettersof reference marked thereon.

My invention relates to an improvement in sewing-machines,andparticularly those of the chain-stitch variety, which employ athread-carrying needle and an under threadcarrying looper and which makea double chain or look chain stitch. WVell-known machines of this classare of the Union Special type, and it is to this particular type ofmachine that my invention is especially applicable and in connectionwith which it is illustrated.

The invention relates particularly to the stitch-forming mechanism ofsuch machines; and its object is to so arrange and time the threeessential elements entering into the stitch-making organization that thelooperthread is spread for the passage of the needle and its thread, thepreviously-formed nee-j dle-loop upon the shank of the looper will beforcibly and positively held away from the descending needle, the slackof the looperthread will be primarily temporarily disposed of orcontrolled by a device not forming a part of the usual take-up or threadcontrolling mechanism, and subsequently such slack will be controlled ortaken up by the usual devices which, though they act later,. willquickly dispose of the last 'vestige ofslack of the looper-thread, thusforming a neat stitch.

As above indicated, there are three ele-' ments inthis organizationwhich constitute the essentials for producing a stitch on my machine,and while these elements may be aided in perfecting the stitch by theusual thread-controlling devices, modified to meet the requirements ofmy arrangement of parts, it is in such elements, their disposition, andlocation, whereby the above results and objects are secured, that myinvention primarily consists. Furthermore, the invention consists in soarranging the so called loopspreader that in its forward movement tospread the looper-loop, in order that the needle may properly engage it,it will pull off through the looper-from the spool more thread than willbe taken up by the looper in its backward movement and more thread thanwill be drawn taut by the take-up, thus adding to the elasticity of thestitch, a very desirable thing in sewing certain classes of goods.

"My invention is illustrated in the accompanying drawings, in .whichFigure 1 is a perspective View of a sewingmachine, partly broken awayand illustrating my invention. Fig. 2 is a front side View of a portionof the bed-plate of a sewing-machine, illustrating myinvention. Fig. 3is a top View showing the loop-spreader at its extreme forward point.Fig. 4 is a top plan 'view showing the loop-spreader at its extremebackward point.

Fig. 5 is a rear end cross-sectional View. Fig. 6 is a front side View,theloopers being shown in dotted lines,

this View being especially to illustrate how the bearing is formed forcarrying the upright shaft upon which the loop-spreader is supported.Fig. 7isafront side view showing the loopers at their extreme forwardpoints. Fig. 8 is an enlarged view showing the looper entering theneedle-loop, the position of its thread, and the thread-groove on theback side of the looper; and Fig. 9 is an enlarged plan view'showing theformation of the stitches.

In the figures, A is the frame of the machine, of ordinary structure,the main shaft '13 being below the bed-plate and receiving its1-I,'having conical recesses h at opposite sides thereof for thereception of conical screws h, affording a support and an adjustablebearing for said carrier. The screws are supported by lugs 72, formingparts of the main frame, and are held in adjustable position by anysuitable device common for that purpose. The looper L is supported inthe upper end of the carrier in any usual or approved manner and isarranged with its longitudinal axis extending lengthwise of the machine.The means for retaining the looper in its carrier will also afford ameans for adjusting said looper vertically and laterally, so that it maybe properly positioned relative to the needle and other parts of themachine. The carrier is provided with a lug or projection h preferablysubstantially spherical, to which is jointed the actuatingconnecting-rod G. It will be seen from this construction that thelooper-carrier has but an oscillating movement in the direction of thelength of the bed-plate and looper and about the conical bearings-thatis to say, for reasons hereinafter stated the looper has no lateralvibration, as is usual in this class of machines, and consequentlytravels on but one side (the rear) of the needle during its operation.The looper is so arranged as to travel at the rear of the needle,considering the direction of feed, and in consequence the looper isgrooved for the reception of the thread on its rear side, as shown at hin Fig. 8, this necessitating the threading of the looper from rear tofront, being the reverse of the usual way.

The loop-spreader mechanism consists of the vertical shaft K, journaledin the inner of the two bearings 72/ and carrying at its upper end thespreader 70, which is held therein by any suitable means which will alsopermit of its being adjusted vertically and laterally for the purpose ofproperly positioning the same relative to the needle and looper. As willbe seen on reference to Fig. i, the spreader is arranged in rear of thelooper, and the shank of the spreader is supported by and is capable ofbeing adjusted in the clamp-conneoting rod or device 70, a recess beingmade in the bearing 77, for the reception of the head of said rod ordevice. The outer end of said rod 7c is preferably spherical, affordinga universal-joint connection with the eccentric-strap k embracing the,-=dle and close to the bed or throat plate.

eccentric on the main shaft B. This mechanism upon revolving the mainshaft causes an oscillating motion to be imparted to the spreader towardand from the plane of movement of the looper and needle and partiallyaround the latter, the disposition of the spreader being above thelooper in rear there of and of the needle, considering the direction ofthe feed, and to the left of the nee- The form of the spreader is bestshown in Fig.

9, where it will be seen that the spreaderblade k is made, preferably,integral with its shank and is provided at its forward end with a notch70 which catches, holds, and carries the looper-thread to the desiredposition; and in order to insure the positive and effectiveengagement'of the spreader with the looper-thread said spreader isprovided with an elongated nose or-finger 7.5, Fig. 9, which in practicemay be suificiently long to always extend into the path of movement ofthe looper-thread, so that as the looper moves forward its thread willcontact with and lie against said nose or finger, thereby assuring theentrance of the thread into the notch of the spreader and the properspreading of the loop of looper-thread for the entrance of the needle.Now while the elongation of this nose or finger is preferable, as abovestated, it is not an essential to the proper working of the machine, andin some cases it may be desirable to dispense with said nose or finger.

As previously stated, the looper is confined to movements in thedirection of its length, and which, as shown in this machine, is alsolengthwise of the bed-plate. In the old fourmotion form of loopermechanism the lateral movements are depended upon for spreading oropening the looper-thread loop for the passage of the needle and forcarrying the needlethread loop upon ,the looper-shank aside in order toavoid the needle, the same movement also making the loopera-voidcollision of the needle therewith in the operation of entering thelooper-thread loop. The two lateral movements of the oldform are doneaway with in my organization, thus reducing the number of parts andsimplifying the machine; but the important advantage is that thepossibility of skipping stitch, ever present in the old form, iscompletely removed in my organization, the spreader always acting withcertainty and precision and performing its functions in a manner torender the skipping of stitches a matter of impossibility.

The description so far, for the sake of simplicity, has been confined toa machine having but one looper and one spreader, as shown in Fig. 1;but in the other figures of the drawings a duplex arrangement isshownthat is to say, two needles, arranged diagonally relative to thedirection of feed, two thread-carrying loopers, arranged one behind theother, the nose of one being slightly in advance of the nose of theother, and two spreaders, arranged side by side and at right angles tothe loopers.

Manifestly the arrangements shown in the drawings are but examples ofthe cooperative relations of the three essential elements which enterinto the stitch-forming operation, and it will be obvious to one skilledin the art that other arrangements of said essentials can be madewithout departing from my invention in spirit or principle. Theneedle-thread is indicated by the numoral l, and the looper-thread bythe numeral 2, and Figs. 8 and 9 show the concatenation of threads inmaking the usual double or look chain stitch.

As a further and special improvement in devices of this character I haveprovided an arrangement whereby the loop-spreader acts to increase theelasticity of the stitch and with this end in view give to the same asuflicient oscillatory movement, as it engages the looper-thread andmoves to its extreme position, that it will draw through the looper-eyefrom the spool a greater amount of thread than the looper in itsbackward movement will take up, therefore leaving a slackness to thestitch on the under side. Of course with this arrangement a special formof cam for the take-up must be used-this a cam which will not eat up allthe slack taken ofi by the loop-spreader.

The operation of the parts thus described is as follows: Rotation of themain shaft imparts an oscillating movement to the looper through itsconnectionwith the needle-arm, and the latter imparts verticalreciprocation to the needle-bar, and the loop-spreader receives anoscillating movement from the main shaft through the describedconnections. The parts are timed and so arranged as to cooperate asfollows: The needle having descended and risen slightly to throw out itsloop, the looper advances and enters said loop at the rear of theneedle, the latter continuing to rise, which needle-loop slips back uponthe shank of the looper. The looper-thread extending from the work orthroat-plate to the eye of the looper is by the continued advance of thelooper brought into a position where the spreader will infallibly engagethe same upon its forward movement, or if the nose of the spreader beelongated, as described, the forward movement of the looper will passits thread into contact with said nose, thus effectually insuring theengagement of the spreaderwiththelooper-thread. Thespreader havingbecome engaged with the looper-thread advances to substantially theposition of Fig. 9, spreading and holding the looper-thread, as shown,so that the needle in making its next or second descent will enter thelooperthread loop. Before the needle completes its second descent,however, the looper recedes, sliding out of the first needle-loop, butleaving its thread therein, which needle-loop is forcibly held back fromthe path of the descending needle by that portion of the looperthreadloop extending from the point of the spreader to the throat-plate orwork. Continued backward movement of the looper draws its thread oi thespreader, the latter in the meantime moving back to its originalposition. As the needle throws out its second loopand the looper movesforward the second time and enters the same the spreader again advances,as before described, to a second time carry the looper-thread forward ofthe path of the needle and hold it open for the entrance of the needleupon its third descent.

Obviously in order to obtain the best results and produce a perfect andneat stitch the looper-thread should be properly controlled in theformation of the stitches, and to that end a take-up mechanism should beemployed, including nipper-springs for holding the thread at properintervals. To obtain the best results in my organization, it becomesnecessary to modify the shape of the take-up cam of the Union Specialmachine, if such be employed, so as to delay the takeup action.

The effect of the cooperation of the three essential elements of this]organization, together with a suitable take-up or thread-controllingmechanism ,is as follows: The spreader will positively place thelooper-thread in position where the needle must pass into the loopthereof. This manipulation of the looperthread causes that strand of theloop which extends from the throat-plate or work to the end of thespreader (in its advanced position) to pass between the descendingneedle and the needle-loop previously entered by the looper, and stillupon its shank, and positively and forcibly hold said needle-loop backand out of the way of the descending needle, (though the looperbereceding,) and thus prevents said needle entering said previouslyformedneedle-loop or becoming entangled with it in any manner, and causes theneedle to certainly pass on the proper side of said needle-loop andaccurately enter the loop of looper-thread. The looper-thread will bekept taut, so as to properly control the needlethread loop which isaround the looper and also to insure the spreader engaging thelooper-thread. The spreader will take up or temporarily dispose ofsubstantially all the slack looper-thread caused by the backwardmovement of the looper up to the time when the needle has reachedsubstantially its lower limit. The continued backward movement of thelooper (the spreader receding) will cause an additional amount of slacklooper-thread, which will be properly taken care of by the take-up orthread-controller, the action of said take-up upon the thread when itacts being quicker than is now common in ma chines of this character,which, as before stated, necessitates a change or modification in theshape of the cam for the purpose of producing the best results.

It will be seen that in the operation of this machine all possibility ofskipping stitches is practically avoided, and loop-retaining wires anddevices may be dispensed with, the loop of needlethread being heldforcibly and positively out of the way of the descending needle.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. A sewing-machine comprising a vibrating looper having a loop-takingand loopshedding movement in the direction of its length, a spreaderhaving movement across the line traversed by said looper in thedirection of the length of said looper and arranged to seize and conveythe looper-thread, and means for imparting to said spreader an amount ofmovement to cause it to pull through the looper a greater quantity ofthread than thelooper will take up in its backward movement;substantially as described.

2. A stitch-forming mechanism for sewingmachines, comprising areciprocating threadcarrying needle, a cooperating thread-carryinglooper, means for actuating the needle and looper, and a spreader withmeans for oscillating it to engage the looper-thread loop, and spread itfor the passage of the needle, said looper and spreader being bothadjustable whereby proper cooperation of the parts may be had;substantially as described.

3. A stitch-forming mechanism for sewing- LANSING ONDERDONK.

Witnesses:

A. H. HATCH, A. L. CooMBs.

